UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Components and Circuits

Notices

Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

Closed Thread
 
Thread Tools
Old 26th Jan 2022, 11:35 pm   #1
Wendymott
Octode
 
Wendymott's Avatar
 
Join Date: Jun 2013
Location: Huddersfield, West Yorkshire, UK.
Posts: 1,782
Default Dymar Modulation meter.

Hi Peeps. I am looking at making a "chinese" copy of the Dymar Modulation meter, however they use two IC's that I have no data on....PA230 some sort of RF opamp. Might even be a LM709 as it has external compensation.
Any ideas ??
__________________
Should get out more.

Regards
Wendy G8BZY
Wendymott is offline  
Old 27th Jan 2022, 12:17 am   #2
Terry_VK5TM
Nonode
 
Terry_VK5TM's Avatar
 
Join Date: Oct 2010
Location: Tintinara, South Australia, Australia
Posts: 2,324
Default Re: Dymar Modulation meter.

How about getting a bit more modern and building something a little simpler?

https://www.vk5dj.com/deviation.html

Only extra needed is a scanner (as in radio scanner) to tap in to.
__________________
Terry VK5TM
https://www.vk5tm.com/
Terry_VK5TM is offline  
Old 27th Jan 2022, 8:58 am   #3
Stockden
Heptode
 
Join Date: Mar 2008
Location: Forest of Dean, Gloucestershire, UK.
Posts: 647
Default Re: Dymar Modulation meter.

I can confirm that the “use an old scanner” approach works well. I have such a modulation meter that I build around 30 years ago to a designing published in 73 magazine. I don’t use it anymore but when I checked it’s calibration a couple of years ago it was still impressively good for such a simple design.

The main down side is that you need to get access to some sort of “standard” in order to set or confirm the calibration (in my case I borrowed a service monitor from work). Of course the scanner needs to cover the frequencies of interest and needs the right channel spacing for what you want.

Hugh
Stockden is offline  
Old 27th Jan 2022, 9:58 am   #4
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
Default Re: Dymar Modulation meter.

Hi Wendy, I may have some '709's from way back if you need any

Ed
Ed_Dinning is offline  
Old 27th Jan 2022, 11:37 am   #5
Wendymott
Octode
 
Wendymott's Avatar
 
Join Date: Jun 2013
Location: Huddersfield, West Yorkshire, UK.
Posts: 1,782
Default Re: Dymar Modulation meter.

Hi Peeps. Haa Haa...... You convinced me Terry. I will do a pcb.. and go from there...
Stupidly I gave away a Dymar Mod meter about a year ago. It was bought as a "donor" and sat in the storage area.... I thought... what a pity to destroy it... so I offered it in the forum.
Well now... building my 2 M TX/RX it is only right that the levels are set correctly and I have a ICOM ICR 7100...... so... there you go. Thanks Ed... but I wont need them now.....
I do a bit on the VHF radio.. then have a few days off....and look at other things...pity I have a super mirrored moving coil meter.....I May just incorporate it
__________________
Should get out more.

Regards
Wendy G8BZY
Wendymott is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 1:45 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.